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"Finally, someone is being held to account for misleading America about the Iraq War," the 'Daily Show' host quipped.

Jon Stewart returned to the Daily Show on Monday and wasn't about to let embattled news anchor Brian Williams off the hook.

Stewart, who was off last week, mocked the controversy surrounding the NBC Nightly News host's story about his 2003 helicopter ride during the Iraq invasion. Williams has apologized for claiming that his chopper took fire, and he is stepping away from anchoring the program for an unspecified number of days.

Stewart played a 2003 Nightly News clip in which Williams said his helicopter was not shot down, which Stewart followed with a 2013 Late Show clip in which Williams told David Letterman it did take fire.

"We got us a case here of 'infotainment confusion syndrome,' " Stewart said about Williams changing his tune on the talk show. "It occurs when the 'celebrity cortex' gets its wires crossed with the 'medulla anchor-dala.' "

Stewart posited that Williams' head turn, as seen when he spoke to Letterman, activated the so-called "celeb-rellum" in his brain. "That's known as the brain's applause center," Stewart continued. "Once that engages, there's no going back. You're in full-blown anecdote mode."

Stewart likened Williams' story to "masturbation," adding: "Self-love can be a bad habit — you probably shouldn't do it at your work desk."

The Daily Show host also took the media to task for focusing so much attention on Williams' apparent fib. "Finally, someone is being held to account for misleading America about the Iraq War," Stewart quipped.